Switch.



G. W. HART.

SWITCH.

APPLIGATION FILED JUNE so, 1910..

987,985. Patented Mar. 28, 1911.

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GERALD W. HART, OF 'WEST HARTFORD, CONNECTOUT, ASSIGNOR T0 THE HART MAN-UFACTURING COMPANY, 0E HARTFORD, CONNECTICUT, A CORPORATION OE NEWJERSEY.

SWITCH.

Specicaton of Letters Patent.

Patented Mar. 28, 1911.

Application tiled June 30, 1910. Serial No. 589,627.

To all whom it may concern:

Be it known that I, GERALD lV. HART, a citizen of the United States,residing at Wvest Hartford, county of Hartford, State of Connecticut,have invented ncertain new and useful Improvements in Switches, of whichthe following is a full, clear, and eX- act description.

My invention relates to improvements in switches, and has for its objectto produce a small and compact switch for breaking a circuit withoutharmful sparking or arcino.

It is particularly designed for circuits having a voltage higher than110 volts,

such, for inst-ance, as a 500 volt circuit or thereabout, which voltagein a switch of ordinary dimensions with no arc preventing means isliable to produce harmful results.

rThe following is a description of a switch embodying my invention,reference being had to the accompanying` drawings, in which- V Figure 1is a plan view of the switch, the cover being omitted. Fig. 2 is a sideelevation of the same. F ig. 3 is a vertical section of the same withthe cover present on the line :U-x, Fig. 1. F ig. 4 is a plan and sideelevation of a detail. F ig. 5 shows a plan view of the switch arm. Fig.6 shows a detail of a stop block, latch and switch plate.

Referring more particularly to the drawings, 1 is a switch base ofporcelain or other suitable insulating material.

2 2 are contact posts.

3 3 are base plates secured to the contact post and themselves securedto therswitch base 1 by screws in the ordinary manner.

rlhe contact posts carry spring contacts h1 -4, which are O-shapedpunchings bent upon themselves, each having one side inserted in a slotin the binding posts at 5, the edges of the slot being upset to hold thecontact member securely in place. lThe engaging portions of the contactmembers 4 lie within large slots 6 formed in the binding posts so as tonot ext-end out beyond the binding posts but to coincide substantiallywith the axes of the posts. TWith this construction of binding post, theswitch arml for a switch with a base of a given diameter can be madevery much longer than it could be made if the contacts extended inwardfrom the binding post toward the axis of the switch blade. The baseplate 3 of the binding post has an inner extension 7 which is bent andscrew-threaded so as to form a screwethreaded bore. The bores are eachprovided with a transverse perforation 8 connecting with holes 9 for theleading-in wire, which passes through the transverse perforation 8 andis secured by a screw 10 engaging screw-threads on the inner surface ofthe bore formed by the bent projection 7.

11 is the shaft of the switch mechanism having within it the spring 12,one end Of which is connected to a spring plate 13, and the other end ofwhich is connected at 14 to a switch plate 14a. The shaft 11 carries arotating member or switch arm carrier 15 secured thereto. To thisrotating member are secured bushings 16, being separated therefrom byinsulation 17.

18 is a switch arm carried by the bushings 16, which pass through thesame, the edges of the switch arm tting loosely in recesses in thebushings so as to permit the switch arm to have considerable play,thereby enabling it to adjust itself to any variation in the position ofthe contacts 4.

The switch is provided with a stop block 18a and a latch 19 moving in arecess in the switch plate 14a, the latch being moved by a pinion 20carried by the spindle 21, to which the handle 22, spring plate 13 andswitch plate 14 are connected, thus producing a quick actingstep-by-step switch mechanism of the general type shown in my Patent No.753,881.

This switch as thus described, on account of the distance between thetwo pairs of contacts 4, has a larger throw and will therefore tend tomore readily break a circuit without arcing when mounted on a base ofgiven di mensions, than a switch with a shorter switch arm, such aswould have to be used with contact posts having inwardly projectingcontact members. There .is still, however, a liability that the arc willfollow the switch arm or jump to the switch mechanism on the breaking ofa circuit and produce damage. In order to prevent this injurious result,I place between the carrier 15 and the switch arm a thin circular sheetof insulating material 23, and above the switch arm 18 place a similarsheet 24 holding the two sheets together and clamped about the switcharm 18 by rivets 25. These two sheets move with the switch arm 18 andare provided with openings, which surround the bushings 16 loosely, soas not to interfere with the move- Les ment of the sheets 23, 2li, orthe movement of the switch arm 18 relatively to the bushings. The endsof the switch arm 1S extend beyond the edges of the insulating sheetssutliciently to pass between the contacts et. The switch mechanism isinclosed in the usual cap 26 with a lining ot paper 27 to thoroughlyprotect it from arcing. wWith such an arrangement, when the switch isoperated, the switch arm 18 moves away from the contacts quickly, and inits place opposite the contacts is substituted a pertion oit' theinsulating disks 23, 2li. Moreover, a portion of the insulating disks23, 24

is interposed in the direct path between the exposed ends of the switcharm and the contacts. TVith such an arrangement, the tendency to arc isvery greatly reduced, and currents ot very considerable voltage can bebroken without the danger of establishing injurious arcs. Theconstruction is simple to manufacture and the operation is etlective.

/Vhat claim is:

l. In a switch, the combination of a quick acting switch mechanism, acarrier rotated thereby, a switch arm supported by said carrier butinsulated therefrom, and sheets of insulating material immediately aboveand below said switch arm fastened together so as to be secured theretoand carried thereby, said switch arm and insulation being mov- `actingswitch mechanism, a switch arm loosely carried thereby but insulatedtherefrom, sheets of insulating material above A and below said switcharm secured together so as to move with said switch arm and be carriedthereby, said switch arm having ends extending beyond the edges oit'said she-ets.

y and contact posts carrying contacts adapted to engage the extremitiesot said switch arm at points approximately in line with the axes of saidcontact posts.

3. ln a switch, the combination oit a quick acting switch mechanism, acarrier rotated thereby having projecting studs, switch arm looselyengaging said studs and sheets of insulating material immediately aboveand below said switch arm tasten-ed together so as to be secured theretoand carried thereby, said switch arm and insulation being movablerelatively to said studs and carrier, said switch arm having its endsextending beyond the edges of said insulating sheets, and contactsengaged by said ends.

GERALD W. HART. 1Witnesses IDA M. HUNZIKER, L. S. JAMES.

Copies of this patent may be obtained for ve cents each, by addressingthe Commissioner of latents, XVashington, I). C.

